There are the five possible known levels of Poltergeist/Ghost activity:

Level 1. Senses Attack

Cold spots, hearing voices, not able to understand what they are saying, strange noises, odd odors & smells, hearing foot steps, unusual animal activity (like dogs or cats running from rooms, etc.) feelings of being watched.

Level 2. Communication                                                                     

Presence felt.... No longer mind tricks

Whispers, laughs or giggles, moans or shrieking, moving shadows, breeze in closed areas, visible clouds (base apparitions) strong static, electricity, marks on the floors or walls- not writing.

Level 3. Electrical Control

Lights & other electrical appliances turning off & on, unseen hands grabbing or touching people, writings on the wall or pattern markings, doors open & close or lock & unlock, hearing voices or words clearly, full apparitions or dark figures, showing levels of communication with living people, strange telephone calls.

Level 4. The Trickery Stage

It gains knowledge of what scares you....Flying objects, moving objects, objects disappearing & reappearing else where, shaking furniture or beds, fire starting, appearing as frightening entities, pushing or shoving people or shaking them, creating visions or illusions, speaking in ordering tones, people feel dizzy, nausea or sick to their stomach, windows, mirrors or other house hold objects breaking for no reason.

Level 5. The Danger Level

Dangerous activity, biting, slapping or punching, rape, animating objects, possession, use of house hold electrical systems to cause harm, fires & burning, blood on the walls-floor or ceilings, attack by unseen forces, held down, hair pulled, flying knives or other sharp objects, heavy objects falling, threatening writings or visual signs.

Poltergeist last for an unknown period of time, but after level 5 it'll lay dormant & then back to

level 1 as it builds up again.